LED Driver Adapted for Gang Boxes

ABSTRACT

A power and control assembly is disclosed. An LED driver is sized and adapted to fit within a single compartment of an electrical gang box. The driver has a groove or channel, and an electrical element, such as a switch, is sized to fit within the groove.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/693,980, filed Sep. 1, 2017, which is a divisional of U.S. patentapplication Ser. No. 15/360,915, filed Nov. 23, 2016, which claimspriority to U.S. Provisional Patent Application No. 62/344,219, filedJun. 1, 2016, and to U.S. Provisional Patent Application No. 62/411,166,filed Oct. 21, 2016. The contents of all of those applications areincorporated by reference in their entireties.

BACKGROUND OF THE INVENTION 1. Field of the Invention

In general, the invention relates to drivers for lighting, and inparticular, to drivers for light-emitting diode (LED) light fixtures.

2. Description of Related Art

Light fixtures that use light-emitting diodes (LEDs) have becomeparticularly popular in both residential and commercial lightingapplications for a variety of reasons, including their relatively highefficiency and adaptability to a variety of different applications.While LED light fixtures are available in various types and with variouspower requirements, a fair number of the LED light fixtures currently onthe market operate at low voltage using direct current (DC) power. Thedefinition of “low voltage” varies depending on the authority oneconsults, but it generally refers to voltages under about 50V.

Low voltage DC poses a problem for fixture designers and for thecarpenters and electricians who install the fixtures: the commercial andresidential power grid operates at a much higher voltage, typically110-240 volts, and uses alternating current (AC) power. Some standardvoltages, particularly for industrial applications, may be higher still.Thus, in order to function in a residential or commercial installation,an LED fixture, e.g., operating at 24 VDC, will require atransformer-rectifier to convert the higher-voltage AC power to 24 VDC.That transformer-rectifier is together referred to as a “power supply,”or a “driver.” Even LEDs designed to operate at higher-voltage DC, e.g.,120V, typically need at least drive circuits and a rectifier, and todrive LEDs that have additional features (e.g., multi-color capability,selectable color temperature, etc.), the driver may need additionalcapabilities to produce power and control signals for those features aswell. Of course, a driver is one more thing that a builder orelectrician must find space to place, often within a wall or in anotherlocation that is hidden and difficult to access.

As LEDs have become more common and accepted in residential andcommercial applications, consumers have sought to do with LEDs the samethings that they are able to do with traditional incandescent lighting.Dimming—the ability to lower the light output of a lamp—is one of thosethings. While LEDs are inherently dimmable, legacy dimmers, intended forincandescent lighting operating on high-voltage AC power, are often notcompatible with LEDs.

There are a number of dimmers that are designed to work with LEDs. Forexample, Elemental LED, Inc. of Emeryville, Calif. sells a combined,integrated driver and dimmer switch under the brand name SWITCHEX®. TheSWITCHEX® driver-dimmer switch is configured to fit within a standardelectrical single gang box (i.e., a standard electrical junction boxconfigured to hold a single light switch). While the SWITCHEX®driver-dimmer switch is innovative and its form factor gives itcompatibility with standard household and commercial lighting circuitswithout having to place a separate driver, the SWITCHEX® does have somedisadvantages.

For one, the SWITCHEX® driver-dimmer switch is limited in the amount ofpower it can handle. Because of applicable standards for Class 2electrical appliances, the SWITCHEX® driver can provide only 60 W (at 12V) or 100 W (at 24 V) of power, whereas traditional dimmers and otherelectrical elements for incandescent lighting may be rated for up to 600W of power.

Additionally, this particular driver-dimmer switch is currentlymanufactured in a limited number of colors and with a limited number ofswitch types and other options, and the aesthetic features of a switchcan matter a great deal. Simply put, most people want all of theirswitches and related hardware to have a similar appearance. However, theconsumer market for electrical switches, dimmers, and other commonelements is controlled by only a few companies, and some switches andswitch styles are protected by various intellectual property rights.Thus, in some cases, even if making a driver-dimmer switch in aparticular style to match other existing fixtures would be possible orpractical, it would be impermissible.

Beyond aesthetics, dimmer switches can be expensive pieces of hardware,and in any given home or commercial setting, there may be quite a few ofthem. Thus, for reasons of cost, convenience, or aesthetic fit, manyconsumers might prefer to keep their existing, legacy dimmer switches,and many installers prefer to buy the simplest components that arecompatible with the greatest number of products.

SUMMARY OF THE INVENTION

One aspect of the invention relates to a system for using LED driverswith traditional alternating current (AC) dimmers and other conventionalcircuit elements. In one embodiment, an LED driver has a form that fitswithin a standard electrical junction box and it and a dimmer areinstalled adjacent one another in a two-gang electrical junction box.The LED driver has an input that, typically, receives alternatingcurrent (AC) power and an output that provides direct current (DC)power, usually at a lower voltage. The dimmer switch receives AC powerat a first voltage or current level, and outputs AC power at a secondvoltage or current level. The output of the dimmer switch is connectedto the input of the LED driver. Thus, a legacy AC dimmer can be usedeasily with an LED driver without having to find a separate space inwhich to install the driver.

Another aspect of the invention relates to methods of connecting the LEDdriver with fascial elements. In some embodiments according to thisaspect of the invention, the fascial elements are nonfunctional ordecorative elements that are placed over or attached to the LED driverto fill space and provide a suitable appearance to the assembly, so thatthe gang box can be fit with a standard cover. These fascial elementsmay include nonfunctional switches and blank plates. In otherembodiments according to this aspect of the invention, the fascialelements may be functional mechanical, electrical, or electromechanicalswitches and controls that are connected to the LED driver to control itor to control the circuit at large. A face plate including a mechanicalswitch may be sized and adapted to be connected mechanically to thecover plate of the LED driver, e.g., with mechanical connectors such ascantilevered snap-fit projections. A switch carried by the face platemay mechanically trigger a button on the cover plate of the LED driver.For face plates with electrical controls, in addition to a mechanicalconnection, signal between the face plate and the LED driver may becarried by, e.g., rigid connectors mounted directly to printed circuitboards (PCB), a wire harness with appropriate connectors, or a ribboncable with appropriate connectors.

Yet another aspect of the invention relates to structures and methodsfor partitioning high voltage and low voltage elements of adriver/dimmer circuit. In embodiments according to this aspect of theinvention, high and low voltage connections are spaced apart on the bodyof an LED driver. A partition is inserted between the high and lowvoltage connections. In some embodiments, the partition may be planar,while in other embodiments, the partition may extend both vertically andhorizontally. The partition may include knock-outs to pass signals fromone compartment to others, and in some cases, the partition may befrangible or include break-lines to alter its size in the field.Depending on the embodiment, the partition may be carried either by theLED driver or by a junction box into which the LED driver is to beinserted.

Other aspects, features, and advantages of the invention will be setforth in the description that follows.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The invention will be described with respect to the following drawingfigures, in which like numerals represent like features throughout theinvention, and in which:

FIG. 1 is a perspective view of a two-gang box with installed dimmer anddriver components;

FIG. 2 is an exploded perspective view of the two-gang box of FIG. 1,illustrating the components installed within it in more detail;

FIG. 3 is a schematic diagram of a four-gang box assembly according toanother embodiment of the invention;

FIG. 4 is a schematic diagram of a circuit including an LED driver, analternating current (AC) dimmer, and an AC switching element;

FIG. 5 is an exploded perspective view of an LED driver and anattachable face plate, illustrating the manner of connection between thetwo;

FIGS. 6-8 are exploded perspective views illustrating various ways ofelectrically connecting an LED driver and an attachable face plate;

FIG. 9 is a rear perspective view of an LED driver with multiple inputsand multiple outputs;

FIG. 10 is a rear perspective view of an LED driver with a single inputand multiple outputs;

FIG. 11 is an exploded perspective view of an LED driver of a differentshape accepting a switch;

FIGS. 12 and 13 are schematic cross-sectional views illustrating theengagement of LED drivers and switching and control elements;

FIG. 14 is a rear perspective view of an LED driver adapted to accept anexternal data connection;

FIG. 15 is a rear perspective view of an LED driver illustrating abarrier between high voltage and low voltage sides of the driver;

FIG. 16 is a schematic cross-sectional view taken through Line 16-16 ofFIG. 15;

FIG. 17 is an exploded rear perspective view of two adjacent drivers ofFIG. 15 with a larger, common barrier between high voltage andlow-voltage sides;

FIG. 18 is a schematic side-elevational exploded view of a gang box anddriver, illustrating a high-low voltage barrier carried by the gang box;

FIG. 19 is an exploded perspective view showing various types ofhigh-low voltage barriers carried by a two-gang box; and

FIG. 20 is a schematic, partially sectional view illustrating the use ofa driver according to the present invention with a hanging fixture.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of a gang box assembly, generally indicatedat 10, that houses an LED driver 12 and a conventional dimmer 14. FIG. 2is an exploded perspective view of the assembly 10. As will be describedin more detail below, the dimmer 14 is typically an alternating current(AC) phase-cut dimmer. The LED driver 12 is electrically connected tothe dimmer 14 and receives its output power signal. The LED driver 12then converts that signal to, e.g., a direct current (DC) signal thatprovides for an appropriate light intensity for the LEDs that it powers.

The gang box 16 itself is a receptacle in which electrical connectionscan be made and components can be installed. It would typically be madeof a plastic or metal, and in a conventional residential or commercialinstallation, would be attached with nails, screws, or otherconventional fasteners, for example, to the interior framing of thehouse. Depending on the installation, insulation may be installed aroundthe two-gang box 16, and a rough opening made in the plaster or drywallovertop it, such that the components are accessible at the surface ofthe resulting wall. A decorative face plate 18 is installed as a toplayer and conceals the opening in the plaster or drywall as well as themounting portions of the other pieces.

The gang box 16 has two open compartments for the installation ofcomponents, hence its name. While a two-gang box 16 is shown in FIGS. 1and 2, embodiments of the invention may use any sort of gang box, andgang boxes with up to five or six different compartments are common.(Gang boxes are also frequently referred to by the number of standardcompartments they have, i.e., a one-gang box, a two-gang box, etc.) Thetwo compartments of the two-gang box 16 are demarcated by fasteningstructures 20, centered at the top and bottom of each compartment, thatare adapted to accept fasteners, like screws, to secure the components12, 14.

In the gang-box assembly 10, the dimmer 14 is a conventional AC dimmer,and may be of any type or features. Typically, the dimmer 14 would be aphase cut type of dimmer, and may be, for example, a magnetic lowvoltage (MLV) or electronic low voltage (ELV) dimmer. The internalworkings of the dimmer 14 are not critical to the invention, although itis assumed in parts of this description that the dimmer 14 will outputan AC voltage.

Installed in the other compartment of the two-gang box 16 is the LEDdriver 12. The LED driver 12 is a fully enclosed element that is sizedto be inserted into a compartment of a standard gang box, like thetwo-gang box 16, to provide power and control for a set of LED lightengines. The LED light engines in question may be linear in form, e.g.,the strip or tape light disclosed in U.S. Pat. No. 9,239,136, thecontents of which are incorporated by reference in their entirety, orthey may be in some other form, e.g., a group of LEDs packaged in theform of a standard, type A lightbulb.

Generally speaking, the dimmer 14 receives AC power at some voltage andcurrent level from the dimmer 14 and generates an output power signalfor the LEDs it controls. The AC power may be at standard household orcommercial voltages (e.g., 110-240 VAC; 277 VAC), or it may be a lowervoltage. (If the dimmer is a low voltage dimmer, either MLV or ELV, thedriver 12 would typically be adapted to receive low voltage AC.) Thepower received by the LED driver 12 may be phase-cut or otherwisemodified by the dimmer 14 and, as was noted briefly above, the LEDdriver 12 converts that power signal into a signal useable by the LEDs.Suitable outputs for the LED driver 12 include, for example, a steady DCvoltage; a pulse-width modulated (PWM) switching output (which istypically a square wave); a constant current output; rectifiedsinusoidal or offset-sinusoidal waves; triangular, sawtooth, and complexwaveforms; or a signal comprised of superposed or “stacked” individualcomponents—such as a combination of a nonzero DC voltage and a PWMsignal, which can be useful over certain portions of the dimming rangeto provide better performance. The output of the LED driver 12 can alsoswitch between types of output signals depending upon where in a dimmingrange it is. For example, over one section of a dimming range, a steadyDC voltage may provide better dimming performance, whereas over anothersection, a PWM signal may provide better performance.

At its rear, the LED driver 12 may include a high-voltage input adapted,for example, to accept 110-240 VAC, depending on the output type of thedimmer 14. The LED driver 12 also includes a low voltage output 24 that,for example, may output 0-50 VDC, depending on the needs of the LEDlighting which it is to power and control. In other embodiments, the LEDlighting may be adapted to accept high-voltage DC, in which case, theLED driver 12 would be adapted to output high-voltage DC. Similarly, ifthe dimmer 14 is adapted to output low-voltage AC power (e.g., 12 or 24VAC), the LED driver 12 would be similarly adapted to receive thatpower. The input 22 and output 24 of the illustrated embodiment are bothgroups of wires.

In some embodiments, electrical codes and regulations may require thatthe compartments of the two-gang box 16 be separated by physical walls,so that there is a physical separation between the low-voltage component(i.e., the LED driver 12) and the high-voltage component (i.e., thedimmer 14), or between low voltage and high voltage sides of acomponent. Thus, as shown in the exploded view of FIG. 2, a verticaldivider 21 is placed in the gang box 16. The divider 21 has twopunch-outs 23 to pass wiring from the dimmer 14 to the LED driver 12.Similarly, the LED driver 12 has a horizontal divider 25 between itsinput 22 and output 24. The horizontal divider 25 fits into a horizontalslot 27 at the rear of the LED driver 12.

The LED driver 12 has a blank, low-profile front plate 26, e.g., made ofa metal or plastic. The front plate 26 has upper and lower flanges 28,each with an opening 30 sized and positioned to allow a screw or otherfastener to secure the LED driver 12 into the fastening structures 20within the two-gang box 16.

There are many options for using the space overtop the LED driver 12,and several of those options are shown in the view of FIG. 2. One optionis the arrangement of FIG. 1—a switch 34 and a decorative faceplate 18with two openings 32, one for each compartment in the two-gang box 16.The switch 34 has upper and lower flanges 36 with first openings 38 thatalign with the openings 28 of the LED driver 12 and second openings 40,spaced slightly more outboard, that align with the openings 40 in thefaceplate 18.

In some embodiments, the switch 34 may simply be a dummy, i.e., presentto fill a hole or present a certain appearance to the end user, butelectrically unconnected to anything. This allows the switch 34 to bechosen so that it matches a desired aesthetic, and manufacturingswitches 34, or other fascia, with desired aesthetic appearances wouldgenerally be easier and less expensive than manufacturing the entire LEDdriver 12 with a particular appearance. Of course, instead of securingseparately, the switch 34 may have structure that allows it to slideonto or otherwise attach to the front plate 26 of the LED driver 12.

Of course, the element placed over the LED driver 12 need not be aswitch—functional or not. As shown in FIG. 2, instead of a switch 34, afixed, decorative “blank” fascial element 35 may be used. If no switch34 or blank element 35 is desired a decorative faceplate 37 may be usedthat has no opening over the compartment in which the LED driver 12 ishoused—it may simply be blank.

In the simplest embodiments, the LED driver 12 may have no externalcontrols—the input 22 and output 24 may be sufficient, and when thedriver 12 takes an input AC voltage signal, it outputs a correspondingDC voltage signal. However, that need not be the case in allembodiments. For example, the LED driver 12 may include an indicatorlight giving its status (e.g., power on/power off/error), and the switch34 or other fascial feature inserted over the LED driver 12, like theswitch 34 or blank 34, may include a window or translucent area throughwhich that indicator light can show. Alternately, the switch 34 or blank35 may include an indicator light that is electrically connected to theLED driver 12, as will be described in more detail below.

In addition, while not shown in the illustrated embodiment, the LEDdriver 12 may have some external controls. For example, the LED driver12 may include an adjustable potentiometer to control trim (i.e., thedimming range). It may also include a control or controls to increase ordecrease output voltage and to adjust output frequency. These controlsmay be accessible on the front plate 26 or sides of the LED driver 12,and would generally be designed to be adjusted by the installer, ratherthan by the end user.

Thus, on the most basic level, the assembly 10 overcomes the limitationsof integrated driver-power supply-switches like the SWITCHEX® describedabove—it allows the installer or end user to have an LED driver 12 thatfits within a standard electrical gang box and also allows the installeror end user to select a dimmer with a look and other fascial featuresthat fit the aesthetic of the room in which the elements are installed.

However, the assembly 10 and other such assemblies according toembodiments of the invention have other advantages and may perform otherfunctions as well. In some embodiments, for example, instead of being amechanical dummy, the switch 34, or another type of control put in itsplace, could be used for switching or control purposes. For example, theswitch 34 could be used as a “zone controller” to allow the user to dimdifferent sections of LED lighting differently. In other cases, theswitch 34 may be wired to control something else. If the switch 34 isadapted to provide a control or switching function, it would typicallyhave wires or other electrical connectors.

As one example, FIG. 3 is a schematic illustration of a four-gang boxassembly 100 according to another embodiment of the invention. In thefour-gang box assembly 100, a conventional AC dimmer 102 is installed inone compartment. The conventional AC dimmer 102 is connected to ACpower, and a divider 104 in the gang box assembly 100 may separate thehigh voltage compartment occupied by the dimmer 102 from the othercompartments. Each of the other three compartments includes an LEDdriver 106, and in the illustrated embodiment, each LED driver 106 iswired to receive the output power signal from the dimmer 102. Each LEDdriver 106 is fronted by a switch 108. However, in contrast to theswitch 34 described above, the switches 108 are functional, and areconnected to their respective LED drivers 106 to convey an on-offsignal. The switches 108 also have some of the features describedabove—in particular, each has an indicator light 110, typically asingle-color or multi-color LED, that indicates power and status forthat driver 106. The indicator light 110 may be implemented either as anLED included in the switch 108 or as a window in the switch 108 thatreveals an LED on the driver 106.

As connected in the view of FIG. 3, the active switches 108 provide atype of zone control. The dimmer 102 provides an output voltage orcurrent level or signal, and the three drivers 106 dim their respectivefixtures 112 in accordance with that signal. However, the user can shutany one of the “zones” off by turning off the switch 108 associated withone of the drivers 106. (If the switches are nonfunctional switches 34,the fixtures 112 would still be controlled by the dimmer 102, but theuser would not be able to switch them off individually.) In FIG. 3, thefixtures 112 may be assumed to be strip lights, but any type of LEDfixture, or any other element that requires the type of power output bythe drivers 106 may be used.

As those of skill in the art will appreciate, the typical paradigm withgang boxes and electrical connections is that one switch, driver, ordimmer powers and controls one electrical fixture. For example, oneswitch will switch one bank of lights on and off. However, gang boxassemblies 10, 100 according to embodiments of the invention may breakfrom that paradigm. In many cases, a single LED driver 12, 106 may berated to handle far more power than is required by a single LED fixture112. Thus, in some cases, a single LED driver 12, 106 may be used topower and drive more than one LED fixture. In the illustration of FIG.3, the right-most driver 106 drives two fixtures 112. The outputs tothose two fixtures 112 may provide the same power level, so as to drivethe two fixtures 112 in the same way, or they may be independent, witheach providing a different drive signal or level of power.

Of course, the illustration of FIG. 3 is but one potential wiringarrangement, and other arrangements are possible. For example, in someembodiments, only one or two of the LED drivers 106 may receive theoutput from the dimmer 102; the other drivers 106 will simply act asswitches in that embodiment. Additionally, it should be understood thatalthough dimmers are shown in these figures, any component that producesan AC output signal may be used in embodiments of the invention. Forexample, a more general home automation process controller may beincluded in lieu of a simple dimmer 102.

The dimmer 14, 102 and drivers 12, 106 are placed in the same gang box16, 100 in the above-described embodiments. However, as those of skillin the art will appreciate, elements in typical lighting circuits areoften separated—for example, two separate switches of different typesplaced on different walls may control the same lighting fixture. Thissort of circuit layout may be used in embodiments of the presentinvention as well.

For example, FIG. 4 is a schematic illustration of a lighting circuit inwhich three one-gang boxes 150 are placed at various locations separatefrom one another, for example, along different walls of a room. A legacydimmer 14 is secured within one of the one-gang boxes 150. Electricallyconnected to the dimmer 14 and spaced from it in its own one-gang box150 is an LED driver 12. The LED driver 12 includes potentiometercontrols for trim and voltage 152, 154. In the illustrated embodiment,the LED driver 12 fits entirely within the one-gang box 150, and theone-gang box 150 is covered by a blank face plate 156.

FIG. 4 also illustrates another possible variation. In the descriptionabove, switches are assumed to be either incorporated into the dimmer 14or attached as face plates to the LED driver 12. However, as shown inFIG. 4, legacy AC switches 158 may also be used in embodiments of thepresent invention, typically as cut-offs for the dimmer 14. While FIG. 4illustrates each component its own one-gang box 150, multiple-gang boxesmay be used for some of the components.

Front-Plate Interconnection

As was described above with respect to FIG. 2, in embodiments of theinvention, the LED drivers 12, 106 may be connected or coupled to anynumber of different styles of face plate, some functional and somenonfunctional. The connection may be purely mechanical or it may be anelectrical interconnect as well.

FIG. 5 is an exploded perspective view of an LED driver 180 and a singleface plate 182 that includes a switch 184. The rear of the switch 184includes several cantilevered snap-fit projections 185 that are designedto engage complementary openings 186 provided in the cover plate 188 ofthe LED driver 180. In the illustrated embodiment, the openings 186 aremore numerous than the projections 185, which gives the driver 180 theability to accept face plates with different configurations. Whilecantilevered snap-fit projections 185 are shown in FIG. 5, it should beunderstood that any cooperating, mechanically-engaging structures may beused in embodiments of the invention. For example, the cover plate 188may have a series of threaded holes, the face plate 182 may havecorresponding holes, and the two components 180, 182 may simply besecured together with machine screws or other, similar fasteners.Additionally, while the face plate 182 carries the “male” features inthe illustrated embodiment and the cover plate 188 of the driver 180carries the “female” features, that may be reversed in otherembodiments.

The connection shown in FIG. 5 may be used purely for attachment, i.e.,to make the LED driver 180 and the face plate 182 into a single,integral unit. However, in some cases, a switching element or anothertype of mechanical control carried by the face plate 182 may be used tocontrol or direct the LED driver 180 using only a mechanicalinterconnect or linkage. As shown in FIG. 5, the cover plate 188 of thedriver 180 may expose a button 190. The switch 184 carried by the faceplate 182 may have a rearward projection 191 that is arranged to actuatethe button 190 when the switch 184 is depressed.

As is also shown in FIG. 5, the cover plate 188 extends into upper andlower flanges 194 that include openings 196 for fasteners, like screwsor nails. The flanges 194 are optional components that allow the driver180 to be secured to drywall and other associated structures.

In many embodiments, it will be advantageous if the driver 180 and theface plate 182 are rigidly connected together to form a unitary whole. Arigid connection between driver 180 and face plate 182 would allow theassembly 180, 182 to be mounted in a gang box just as a conventional ACswitch or dimmer is mounted. However, in some embodiments, the driverand face plate may have a more flexible connection.

FIGS. 6-8 are exploded perspective views illustrating other embodimentsof LED drivers and face plates with different forms of electricalinterconnection. In the view of FIG. 6, the face plate 200 has a printedcircuit board (PCB) 202 that includes circuitry for the control elementsof the face plate 200. These control elements may be, e.g., a switch, atimer, a color controller, a touch screen, etc. Mounted on the PCB 202,by surface mount or other technique, is an electrical connector 204,which extends rearwardly. The face plate 200 also includes mechanicalengaging elements, such as cantilevered snap-fit connectors 206. Thedriver 210 has a cover plate 212 with openings 214 for the mechanicalconnectors 206 to engage, as well as a complementary electricalconnector 216. The precise type of the electrical connector 216 is notcritical, although in this particular illustrated embodiment, it ishelpful if the electrical connector 216 fosters a rigid connectionbetween the driver 210 and the cover plate 212. For example, anothersimilar technique would involve using so-called “pin header connectors.”In this arrangement, one PCB has bare pins protruding and the other PCBhas receptacles for the pins.

In FIG. 7, the face plate 230 has a connector 232 mounted on its PCB234. A wire harness 238 capped with a complementary connector 240extends from the cover plate 236 of the corresponding LED driver 242.The face plate 230 also carries mechanical connectors 206, again in theform of cantilevered snap-fit projections, although in some embodiments,these may be omitted.

In FIG. 8, the face plate 250 has a ribbon cable and connector 252mounted on its PCB 254. The cover plate 256 of the corresponding LEDdriver 258 carries the corresponding connector 260 for the ribbon cableand connector. FIGS. 6-8, of course, are only three examples of thetypes of mechanical and electrical interconnections that can be used. Aswith other features, which of the components carries the “male”structures and which carries the “female” structures may vary fromembodiment to embodiment. In addition to the features above, each of thedrivers 210, 242, 258 in FIGS. 6-8 includes a cover plate 212 that hasside flanges 215 that may make it easier to manipulate the driver 210,242, 258 and may prevent the driver 210, 242, 258 from sinking too farback into a gang box.

Of course, not all face plates need carry control elements, likeswitches. Some face plates may instead carry LEDs to indicate the statusof the driver 210, 242, 258 (e.g., on/off, dimming level) or, in othercases, display panels, such as LCD display panels.

As can be seen in each of FIGS. 6-8, the LED driver 210, 242, 258carries standard wires for AC input and output. Typically, these includehot, neutral, and ground wires 270, 272, 274. As shown, each LED driver210, 242, 258 also includes positive and ground wires 276, 278 for DCvoltage output. Depending on the particular embodiment, there may beother wires or signal-outs provided. In general, the LED drivers 12,180, 210, 242, 258 described here may be configured to drive a widevariety of different types of LEDs including single color LEDs;two-color or adjustable color temperature LEDs (typically requiring 3wires); red-green-blue (RGB) selectable color LEDs (typically requiring4 wires); RGB-white and RGB-amber LEDs (typically requiring 5 wires);and LEDs that require more wires or data lines for control. In addition,the drivers 12, 180, 210, 242, 258 described here may be used to powerand control any type of constant voltage or constant current fixtures.

While certain portions of this description refer to wires as the primarymeans for power and signal input and output, and wires are thetraditional means of connection in household and commercial electricalcircuits, in other embodiments, any means of carrying an electricalsignal may be used. Particularly if the LEDs in question require or usemultiple wires, other means of connection may be helpful. Otherpotential signal carriers that may be used in some embodiments includecables that use twisted pairs of wires, coaxial cables, and ribboncables.

The description above notes that in some cases, one driver may powermore than one fixture, or more generally, that there need not be aone-to-one correspondence between a single driver and a single LEDluminaire to be powered and controlled. FIG. 9 is a rear perspectiveview of a driver 280 that has two sets of inputs 282, 284, which wouldtypically be AC inputs, and two sets of outputs 286, 288. The outputs286, 288 may be the same voltage or different voltages (e.g., one 12 VDCoutput and one 24 VDC output), and they may have the same outputwaveform or different output waveforms, as explained above.

Similarly, FIG. 10 illustrates a driver 300 with a single input 302 andmultiple outputs 304, 306, 308. As with the driver 280, the input 302would typically be an AC input, and the outputs 304, 306, 308 may be thesame or different voltages, and they may generate the same or differentoutput waveforms.

FIGS. 9 and 10 also illustrate a feature of the drivers 280, 300 thatmay be used in a variety of embodiments: rather than includinghardwired, permanently attached output wires, the inputs 282, 284, 302and outputs 286, 288, 304, 306, 308 may instead comprise terminalblocks, into which wires of suitable lengths can be inserted to connectthem. Screw terminals or other such electrical connections may be used.The use of terminals, rather than wires connected at the time ofmanufacturing, gives the installer more flexibility.

In the description above and in the figures, the LED drivers 12, 180,210, 242, 258 are generally rectilinear in shape, sometimes withtruncated or rounded corners, and the appropriate face plate cover fitsovertop of the driver. However, so long as it will fit in a standardelectrical gang box (whether a one-gang box, a two-gang box, etc.), theprecise shape of the driver is not critical. FIG. 11 is a schematicexploded perspective view of a driver 320 that, while it has generallyrectilinear features, also has a deep rectangular channel 322 in thecenter of the front face 324. Instead of merely resting on or againstthe front of the driver 320, a switch 326 fits within the channel 322.Standard mechanical elements, like cantilevered snap-fit projections206, may be used to connect the two. If a snug fit (or press fit) isdesired between the switch 326 (or other element) and the driver 320,instead of a connector, ribbon cable, or other such connection means, aset of conductive contacts 328 may be provided on the side or sides ofthe switch 326, positioned to mate with complementary contacts on thesidewalls of the channel 322. The contacts 328 on the switch 326 or thecomplementary contacts on the sidewalls of the channel 322, which arenot visible in the view of FIG. 11, may be spring-loaded to facilitatepositive connection between the two. The driver 320 itself may be sizedto fit within a one-gang box, a two-gang box, or any other standardelectrical junction box. Of course, it may be advantageous if thecombination 320, 326 can fit within a one-gang box.

FIG. 11 is only one example of how a driver 320 and a switching orcontrol element 326 may be shaped and configured in complementary ways.However, other configurations are possible. FIGS. 12 and 13 areschematic cross-sectional views illustrating alternate configurations.In FIG. 12, a switching element 330 is enveloped by a driver 332 thathas a channel 334 or depression. In FIG. 13, a switching, control, ordisplay element 340 has a larger extent within the junction box 150, andthe driver 342 is placed in the space behind it.

FIG. 14 is a rear perspective view of a driver 350 according to anotherembodiment of the invention. In addition to an input terminal block 352and an output terminal block 354, the driver 350 includes a jack 356 foran Ethernet cable 358. While much of this description focuses on drivingand dimming LEDs, there are a variety of scenarios in which a driver 350may require, or create additional benefit, when connected to a local orwide-area computer network, such as the Internet. For example, the faceplate connected to the driver 350 may have household automation controlsthat require connection to a network so that, e.g., lighting can beturned on and off by controls on the face plate or by an applicationrunning on a computer or on a computing device like a cell phone ortablet. Of course, a hard-wired connection using an Ethernet cable 358is not the only way of connecting to a computer network. In variousembodiments, the driver 350 may connect to a network by other forms ofwired connection, for example, using a coaxial cable, or it may connectto a network using a number of different types of wireless networkingtechnologies, including IEEE 802.11 a/b/g/n/ac (WiFi), IEEE 802.15.1(Bluetooth), near-field communication, and other common wirelessnetworking protocols and technologies.

In addition to receiving information from external sources andcontrolling its LEDs in accordance with that information, the LEDs mayinstead be used to transmit data themselves. Visible light communication(VLC) has long been known in various forms, and in recent years, variousentities have explored using LEDs to transmit data. In this type ofnetwork, LEDs are driven by a high-frequency signal that is modulated tocarry data. The high frequency of this modulation—typically in thegigahertz range—is invisible to the human eye, and thus, the LEDs do notappear to flicker. Modulation formats like on-off keying and variablepulse position modulation can be used to encode data, and an opticalsensor can be used to receive the data. Regardless of the particularprotocols used, the data jack 356 in the driver 350 may be used toaccept data that is to be transmitted by the LEDs to which it isconnected, and the driver 350 may also include an optical sensor orsensors and circuits to demodulate data that is received and route it tothe jack 356 for outbound transmission.

In the context of this invention, if necessary or desirable fornetworking or other purposes, components other than standard lightingcomponents may be included in the electrical junction boxes, withlarger, multi-position boxes being used to hold the additionalcomponents.

Separation of High- and Low-Voltage Components

As was described briefly above, electrical codes or other requirementsmay require the physical separation of high-voltage and low-voltageelements in a household or business electrical circuit. Since LEDdrivers according to embodiments of the invention include bothhigh-voltage inputs and low-voltage outputs, barriers like the barrier21 of FIG. 2 may be included.

FIG. 15 is a rear perspective view of an LED driver 400. The driver 400has a high-voltage AC input terminal block 402 toward its rear bottom. Alow-voltage output terminal block 404 is provided in the upper rightcorner. A horizontal barrier 406 is seated in a horizontal groove 408provided across the rear of the driver 400. FIG. 16, a cross-sectionalview taken through Line 16-16 of FIG. 15, schematically illustrates howthis would appear in a junction box—the barrier 406 projects rearwardlyfrom the driver 400 to isolate the high voltage and low voltage sides.Another feature of the barrier 406 is shown in the view of FIG. 15: thebarrier 406 has two frangible portions 410 defined by break lines 412 inthe barrier 406. These frangible portions 410 can be broken off of thebarrier 406 to shorten it, if necessary, at the time of installation. Ofcourse, frangible portions 410 and break lines 412 are optionalfeatures, and may not be present in all embodiments.

As described above, there are embodiments in which multiple drivers 400may be placed adjacent one another in a multiple-gang box. FIG. 17 is anexploded rear perspective view of two drivers 400 with rear, horizontalgrooves 408. Instead of using a single barrier 406 in each of thesegrooves, as illustrated in FIG. 17, a larger barrier 414 is used. Thebarrier 414 has two C-shaped cut outs 416 that define a tongue 418 thatextends between the two drivers 400 and tongues 420 that extend to theleft and right sides of the drivers 400, in order to foster a morecomplete separation between high and low voltage.

In some embodiments, the barrier 406, 414 need not be carried by thedriver 400. Instead, as shown in the schematic exploded side-elevationalview of FIG. 18, a barrier 450 may be carried in a slot or groove 452along the rear of a gang box 454. When a driver 456 is inserted into thegang box 454, the barrier 450 separates high- and low-voltage sides.

Especially in multiple-gang boxes, barriers of different characteristicsmay be used. FIG. 19 is an exploded perspective view of a two-gang box500. The two-gang box 500 has interior slots or grooves 502 locatedalong each face, between positions along its long side and mid-way upalong its vertical walls. Two options for potential barriers are shownin FIG. 19. One option is a simple horizontal barrier 504 to dividebetween high voltage and low voltage areas, assuming that the highvoltage area is located toward the top and the low voltage area islocated toward the bottom, or vice-versa. The other option shown in FIG.19 is a cross-shaped barrier 506 that extends both horizontally andvertically, seating in all four of the grooves 502 in the two-gang box500. The barrier 506 divides the two-gang box 500 into high-voltage andlow-voltage areas, and also provides vertical barriers 507 betweenadjacent components. Cut-outs 508 are formed in the vertical barriers507 in order to pass high-voltage and low-voltage wires, respectively,between adjacent components in the two-gang box 500. In someembodiments, there may be frangible portions that are broken out at thetime of installation to form the cut-outs 508.

Hanging Fixtures

Most of the disclosure above focuses on the placement of drivers 12, 106in gang boxes 16 within vertical walls. However, there are a number ofsituations in which it is desirable to place a gang box 16, or anotherkind of junction box, in a ceiling. This is useful, for example, whenone wishes to use a hanging light fixture, or another element, like aceiling fan, that requires an electrical connection. Embodiments of theinvention may be adapted to hanging-fixture scenarios.

More particularly, FIG. 20 is a schematic, partially sectional view of ahanging light fixture, generally illustrated at 600, showing itsattachments. The light fixture 600 of FIG. 20 is in the form of anextrusion, although pendant lighting of various types may also be used.With respect to extrusions, U.S. Pat. No. 9,279,544, the contents ofwhich are incorporated by reference, discloses a number of extrusionsthat may be used with linear LED lighting, and for purposes of thisdescription, the light fixture 600 may be assumed to be an extrusionwith linear LED lighting mounted within and, optionally, a diffuserovertop.

On or near one end, the extrusion 600 is connected to the ceiling 602 bya thin, downwardly extending conduit 604 which may be, e.g., made of ametal. On or near the other end, the extrusion 600 is supported byanother means, such as a thin metal wire 606, although in otherembodiments, the two mountings 604, 606 may be the same. As is typicalin residential and commercial settings, a junction box 608 is mounted inthe ceiling 602. The illustration of FIG. 20 assumes that only onejunction box 608 is available in the area in which the light fixture 600is to be installed; if more than one junction box 608 is available, morethan one may be used.

If the junction box 608 is large enough, a driver 12, 106 may beinstalled in it as in other embodiments. Because the junction box 608 isin the ceiling, as in the arrangement of FIG. 4, control elements likeswitches and dimmers are typically located elsewhere in the electricalcircuit, where they can be accessed and used more easily. However, insome cases, a switch, dimmer, or other control element that takesinfrared or radio input (e.g., from a remote control or a homeautomation system) may be installed in the junction box 608.

In FIG. 20, a driver 610 is installed. However, the driver 610 does notfit entirely within the junction box 608. Instead, the driver 610 usessome of the space covered by the canopy 612, the usually decorativefitting that covers the junction box 608. In some cases, the driver 610may be arranged as the other drivers described above are arranged: withhigh-voltage inputs and low-voltage outputs both located in the rear.However, the driver 610 of FIG. 20 is arranged somewhat differently,with high-voltage input and ground terminals on one side of the driver610 and low-voltage output and ground 616 on the other side. Thelow-voltage output wires 616 travel down the conduit 604 to the lightfixture 600. A partition or partitions 618 are attached between thedriver 610 and the interior sides of the canopy 612 or junction box 608to separate high voltage from low voltage.

As the above description bears out, while the high-voltage inputs for adriver according to embodiments of the invention are usually at therear, and the low-voltage inputs are usually also at the rear, thatarrangement may vary. There may be situations, like that in FIG. 20, inwhich it is more convenient for a driver 610 to have low-voltage outputson the front cover plate 26. Ultimately, the inputs and outputs may bein any convenient or necessary locations.

Beyond powering lighting fixtures, a number of devices are powered orcharged with low-voltage DC, and in some embodiments, the driver 610 mayhave a low-voltage output jack, either on its body or on a face platethat is removably attached to the driver 610, as in FIGS. 6-8. A jack,as compared with wire terminals, would allow portable fixtures and otherelectronic devices to be powered. If a jack is used, the jack may be ofa standard type, such as a barrel connector socket or a USB or USB-Csocket.

While the invention has been described with respect to variousembodiments, the description is intended to be exemplary, rather thanlimiting. Modifications and changes may be made within the scope of theinvention, which is defined by the appended claims.

What is claimed is:
 1. An electrical control assembly, comprising: adriver having an input adapted to accept power in a first form and anoutput adapted to provide power in a second form that is different fromthe first form, the driver having a channel therein; and an electricalcontrol element adapted to fit within the channel of the driver and toconnect electrically with the driver; wherein the driver and theelectrical control element are sized to fit within a one-gang box. 2.The electrical control assembly of claim 1, wherein the input of thedriver accepts high-voltage, alternating-current (AC) power, and theoutput provides low-voltage, direct-current (DC) power.
 3. Theelectrical control assembly of claim 2, wherein the electrical controlelement provides an electrical control signal to the driver.
 4. Theelectrical control assembly of claim 3, wherein the driver furthercomprises one or more electrical contacts in the channel, and theelectrical control element has one or more complementary electricalcontacts adapted to connect to the one or more electrical contacts inthe channel.
 5. The electrical control assembly of claim 2, wherein theoutput is connected, directly or indirectly, to low-voltage lighting. 6.The electrical control assembly of claim 2, wherein the electricalcontrol element comprises a switch.
 7. The electrical control assemblyof claim 2, wherein the electrical control element comprises a dimmer.